我国原生汞生产行业典型企业Hg的污染排放特征

为了解目前国内仍在运行生产的原生汞生产企业各排污节点气态Hg排放现状以及对周围环境介质的影响,选择一家典型企业进行了现场监测研究. 结果表明:在研究企业汞矿坑口、中转漏斗、破碎、浮选、脱水等工艺节点的车间空气中ρ(气态Hg)较低,在(3.00±0.23)~(20.3±7.7)ng/m3之间；而在全尾砂充填、冶炼和冷凝等工艺节点的车间空气中ρ(气态Hg)相对较高,为(754±67)~(907±79)ng/m3. 冶炼废气中ρ(气态Hg)平均值为(295±32)μg/m3,ρ(颗粒态Hg)平均值为(65.9±3.8)μg/m3；燃煤锅炉废气中ρ(气态Hg)平均值为(123±40)μg/m3,未达到GB 30770—2014《锡、锑、汞工业污染物排放标准》限值(15 μg/m3)或GB 13271—2014《锅炉大气污染物排放标准》限值(50 μg/m3)的要求,其ρ(颗粒态Hg)平均值为(14.1±3.5)μg/m3,ρ(气态Hg)∶ρ(颗粒态Hg)约为7∶1. 研究企业2012年气态Hg排放总量为18.9 kg,释Hg因子为0.004 8%. 研究企业矿区内土壤w(总Hg)为6.44~444 mg/kg,平均值为(140±133)mg/kg；矿区外为1.96~104 mg/kg,平均值为(24.4±26.2)mg/kg. 地累积指数法评价结果表明,土壤受Hg污染影响程度为矿区内>矿区外东南和东北方向>矿区外西南和西北方向. 研究显示,我国汞矿开采、冶炼排放对厂界及周边土壤造成了明显影响,并且污染仍在持续,不容忽视. 

Mercury Pollution Characteristics of Industrial Companies in Primary Production Industry of China

The gaseous mercury emissions from each procedure of a typical primary mercury producer were characterized. On-site monitoring was carried out in December 2012. The analytical results revealed that:1) the concentration of gaseous mercury in the workplace air of the main process nodes,such as mercury mine pit,transit funnel,crushing,flotation and dewatering,were in low ranges from (3.00±0.23)ng/m3 to (20.3±7.7) ng/m3,while those of other nodes,such as total tailing filling,smelting and condensing,were relatively high with values from (754±67)ng/m3 to (907±79) ng/m3. 2) The average concentration of gaseous mercury in smelting exhaust was (295±32) μg/m3,and the particulate mercury was (65.9±3.8)μg/m3. However,the gaseous mercury in the boiler exhaust was (123±40)μg/m3,while the particulate mercury was (14.1±3.5)μg/m3. The total mercury concentration was not in compliance with the emission limits specified in GB 30770-2014 Emission Standards of pollutants for stannum, antimony and mercury or in GB 13271-2014 Emission Standard of Air Pollutants For Boilers. The ratio of exhaust gaseous mercury to particulate mercury was about 7∶1. The total gaseous mercury emissions from the industrial companies in 2012 were 18.9 kg,and thus the mercury release factor was 0.0048%. 3) The mercury content in soil samples varied. Inside the Hg-mining area it was (140±133) mg/kg on average,whereas for outside samples,it was (24.4±26.2) mg/kg. The accumulative evaluation index indicated that the impact of soil mercury contamination decreased in the following order:mining area > southeastern and northeastern sites outside mining area > southwestern and northwestern sites outside mining area. The significant impact on the soils surrounding the enterprise should not be ignored due to excessive gaseous mercury emissions from the production of mercury.